A power transmission device for a vehicle is known in which a transmission clutch is interposed between an engine and a manual transmission, and the transmission clutch is automatically connected and disconnected when the transmission is shifted as disclosed in Japanese Patent Application Laid-Open No. 2002-295673.
The transmission clutch is disconnected by a control means when the transmission is shifted before the gears are disengaged and connected after the gears are engaged. More specifically, the transmission clutch is operated by a fluid pressure (oil pressure), and a control valve is provided in a pipe supplying the oil pressure to the transmission clutch.
The inventors are currently in the process of developing a transmission clutch control device that employs a linear solenoid valve, in which an opening degree is changed in correspondence with a supplied current value, as the control valve.